1. Field of the Invention
The present invention relates to an apparatus for performing functional tests on LSI mounted on a board and particularly, to a test apparatus for a bare-chip LSI mounting board to perform a high-speed test in a short time.
2. Description of the Related Art
It has been hitherto difficult to perform a functional test at an actual speed on a bare-chip LSI alone. Therefore, it has been generally adopted to perform the functional test after a bare-chip LSI is mounted on a board and also SMT (surface mount technology) parts such as RAM, capacitors and resistors are mounted on the board. However, in this case, a conduction failure of the bare-chip LSI to the board, functional defects of the bare-chip LSI itself, or the like are found at the final stage of the manufacturing process, and thus the loss in productivity is increased. That is, even when the test failure is caused by the defect of the bare-chip LSI itself, a print board and other SMT parts which have been already mounted must be wasted.
The present invention has an object to provide a bare-chip LSI mounting board testing apparatus which can find a conduction failure, functional defects, or the like at such an early stage that a bare-chip LSI is mounted on a board before SMT parts such as RAM, capacitors and resistors are mounted, thereby reducing the loss in productivity.
Therefore, according to the present invention, a bare-chip LSI mounting board test apparatus comprising: at least one tester board which equivalent parts corresponding to mount parts other than a bare-chip LSI to be mounted on a board are mounted, probes connected to the respective equivalent parts of the tester boards, driving means for bringing the probes into contact with pads located at the mount places of the mount parts on the board to build a quasi-mount state of the mount parts to the board, and a controller for transmitting a test signal to the bare-chip LSI under the quasi-mount state. SMT parts having no leads. SMT parts having no leads and parts such as RAM, capacitors and resistors having leads, or parts such as RAM, capacitors and resistors having leads can be used as the mount parts.
In this case, as a preferable embodiment of the present invention, the tester boards have the respective equivalent parts mounted thereon in the same arrangement as the SMT parts, and the pair of tester boards are arranged so that the probes are arranged so as to be brought into contact with and detached from the respective pads on both surfaces of the board. Further, the controller of the high-speed tester transmits the test signal through the tester boards to the bare-chip LSI of the board.